Fix remote URL test (#237)
Fix remote URL test (#237)

When this test was originally created, an HTTP get to
`https://url.com/something/not/real` probably failed, but now it
will return a `503`, i.e. the `http.Get` call will succeed.

This test will now use a URL which should not reasonable ever
succeed (famous last words). Alternatively we could use dependency
injection and mock `http.Get` but it doesn't seem worth it.

This commit also updates the test to use `Run` to run each test
in the table test as a separate test so we can get a clear indication
which cases fail and which succeed.
GoogleContainerTools/kaniko,GoogleContainerTools/kaniko,GoogleContainerTools/kaniko